This invention relates to a hydraulic control system for aerial boom devices.
Heretofore, in the usual hydraulic system for aerial boom devices that is pressure sensitive, a piston in the system connected to the speed control of the pump is activated to increase the engine speed as a control valve is operated. Another method of pump speed acceleration uses an electrical two-speed control. These types of speed control systems are located on the high-pressure side of the system and often result in dead time when the pump is accelerating while a pressure increase is not needed.